The four hus are divided into Mongolian four-hus, high-pitched four-hus, mid-voiced four-hus, low-pitched four-hus, Yi four-hus, and Buyi four-hus. They are mainly popular in Inner Mongolia, and are also found in other places such as Shanxi, Shaanxi, Hebei, Henan and Sichuan. Popularity. Mongolian Sihu Treble Sihu Mongolian bow and stringed musical instruments. Also known as Mon...